In recent years, as portable electronic devices (e.g., mobile phones and digital cameras) become ubiquitous, much effort has been put into reducing dimensions of portable electronic devices. Moreover, as dimensions of charged coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) based optical sensors are reduced, dimensions of imaging lenses for use with the optical sensors must be correspondingly reduced without significantly compromising optical performance. Imaging quality and size are two of the most important characteristics for an imaging lens.
However, in optical lens design, to reduce proportionally a size of an imaging lens is insufficient to enable such an imaging lens to be miniaturized while maintaining imaging quality. In the design process, material properties and assembly yield of such an imaging lens should also be considered.
Therefore, greater technical difficulties are encountered for a miniaturized imaging lens than for traditional imaging lenses. Producing an imaging lens that meets the requirements of consumer electronic products while having satisfactory optical performance is always a goal in the industry.